To enhance resolution while keeping the dry etching resistance of the positive photoresist composition by using a specified photodecolorable compound as a dissolution preventer.
The positive photoresist composition to be used for far ultra-violet rays contains a (meth)acrylic polymer, an acid photogenerator, and the dissolution preventer which is at least one kind of photodecolorable compound selected from vitamin A group or a vitamin D group. This photodecolorable compound has a decolorability of a property of absorbing ultraviolet rays lowering at first, when it is exposed to far ultraviolet rays, especially, those of 193nm wavelength, and consequently, when the resist-coated film comprising this composition is exposed to the far ultraviolet rays, the light transmittance of the exposed part becomes higher than the surrounding unexposed part with the lapse of time, and the contrast of the transmittance between them increases, thus raising the resolution of the positive photoresist.